[chirp_devel] [PATCH] [FT-70] New Model #5329 Increased second block size

[Brian Dickman]

On Wed, Mar 21, 2018 at 4:06 PM, Dan Smith via chirp_devel
<chirp_devel at intrepid.danplanet.com> wrote:
>> The FT70 has a built in USB interface The Chirp driver is only intended to be used with this, no baud rate is set on it. Using a higher baud rate made a slight difference in speed, But initially thought this might now be causing other issues, so changed back to 38400.
>
> That is very surprising to me. Every other USB serial device I know of honors the baud rate as expected. Unless the radio is really mirroring whatever it can tell the USB serial bridge is set to, but that would be the first such device I've ever encountered.

A quick inspection of the FT70 firmware package from Yaesu shows this
is a Renesas microcontroller with a native USB port. In this case it
emulates a serial port directly in firmware, rather than a separate
USB-serial bridge chip. That's probably a first for an HT, but it's
pretty common in the wider microcontroller world.

On devices like that, they just absorb the baud rate changes and
pretend to be running at that rate, but it's a no-op inside the
microcontroller. Because of this, the actual data rate over the wire
can be much faster, since it's only limited by USB data rate and
microcontroller speed.

Nicolas, I wouldn't worry about the baud rate changes; just leave it
how it was and it should work fine and operate at max throughput
regardless. However, changing it also shouldn't cause issues.

--
Brian